Creating Resolvers

A Resolver should be created for any plugin type. Resolvers are the standard way to retrieve/create/register plugin types.

Creating a single object resolver

As an example, we'll create a resolver to resolve an application error logger:

All you need to do is inherit from Umbraco.Core.ObjectResolution.SingleObjectResolverBase<TResolver, TResolved> and then add whatever constructors, properties and methods you would like to expose.

In the example above we have a constructor that accepts a default IErrorLogger. Normally in Umbraco this resolver will be constructed in a IBootManager with a default object. The we expose a method to allow developers to change to a custom IErrorLogger at runtime called SetErrorLogger. Then we create a property to expose the IErrorLogger called ErrorLogger.

Example:

Creating a multiple object resolver

Creating a multiple object resolver is similar. As an example we'll create a LanguageConvertersResolver.

When creating a multiple object resolver you need to decide what lifetime scope the objects created and returned will have which is defined in the constructor created. The default constructor of the ManyObjectsResolverBase specifies that the objects created will have an Application based lifetime scope which means the objects will be singletons only one instance of each one will exist for the lifetime of the application. There are 3 lifetime scopes that can be specified:

• ObjectLifetimeScope.Application

  • One instance of each object will be created for the entire lifetime of the application (singleton)

• ObjectLifetimeScope.Transient

  • A new instance of each object will be created each time the 'Values' collection is accessed

• ObjectLifetimeScope.HttpRequest

  • One instance of each object will be created for the lifetime of the current http request